Too much sitting, too little exercise may accelerate biological aging

Researchers at University of California San Diego School of Medicine report that elderly women who sit for more than 10 hours a day with low physical activity have cells that are biologically older by eight years compared to women who are less sedentary.

The study, publishing online January 18 in the American Journal of Epidemiology, found elderly women with less than 40 minutes of moderate-to-vigorous physical activity per day and who remain sedentary for more than 10 hours per day have shorter telomeres -- tiny caps found on the ends of DNA strands, like the plastic tips of shoelaces, that protect chromosomes from deterioration and progressively shorten with age.

As a cell ages, its telomeres naturally shorten and fray, but health and lifestyle factors, such as obesity and smoking, may accelerate that process. Shortened telomeres are associated with cardiovascular disease, diabetes and major cancers.

"Our study found cells age faster with a sedentary lifestyle. Chronological age doesn't always match biological age," said Aladdin Shadyab, PhD, lead author of the study with the Department of Family Medicine and Public Health at UC San Diego School of Medicine.

Shadyab and his research team believe they are the first to objectively measure how the combination of sedentary time and exercise can impact the aging biomarker.

Nearly 1,500 women, ages 64 to 95, participated in the study. The women are part of the larger Women's Health Initiative (WHI), a national, longitudinal study investigating the determinants of chronic diseases in postmenopausal women. The participants completed questionnaires and wore an accelerometer on their right hip for seven consecutive days during waking and sleeping hours to track their movements.

"We found that women who sat longer did not have shorter telomere length if they exercised for at least 30 minutes a day, the national recommended guideline," said Shadyab. "Discussions about the benefits of exercise should start when we are young, and physical activity should continue to be part of our daily lives as we get older, even at 80 years old."

Shadyab said future studies will examine how exercise relates to telomere length in younger populations and in men.

Are US adults meeting physical activity guidelines?The proportion of US adults adhering to the 'Physical Activity Guidelines for Americans' from the US Department of Health and Human Services didn't significantly improve between 2007 and 2016 but time spent sitting increased.

Trending Science News

Top Science Podcasts

Clint SmithThe killing of George Floyd by a police officer has sparked massive protests nationwide. This hour, writer and scholar Clint Smith reflects on this moment, through conversation, letters, and poetry.

#562 Superbug to BedsideBy now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.

GrahamIf former Minneapolis police officer Derek Chauvin's case for the death of George Floyd goes to trial, there will be this one, controversial legal principle looming over the proceedings: The reasonable officer.
In this episode, we explore the origin of the reasonable officer standard, with the case that sent two Charlotte lawyers on a quest for true objectivity, and changed the face of policing in the US.
This episode was produced by Matt Kielty with help from Kelly Prime and Annie McEwen.
Support Radiolab today at Radiolab.org/donate.